Add bind() function to the binder interface.

Update engine may have started and done some work before we call
applyPayload(). Add a new binder function bind() to register a
callback function that communicates with the update engine.

Bug: None
Test: 'mmma system/update_engine'.
Change-Id: Iafcdb250904b44f9526be15f0381690df50805a2
diff --git a/binder_service.h b/binder_service.h
index bbbe5b6..71b9778 100644
--- a/binder_service.h
+++ b/binder_service.h
@@ -24,7 +24,7 @@
 #include <utils/StrongPointer.h>
 
 #include "android/os/BnUpdateEngine.h"
-#include "android/os/IUpdateEnginePayloadApplicationCallback.h"
+#include "android/os/IUpdateEngineCallback.h"
 
 namespace chromeos_update_engine {
 
@@ -35,10 +35,11 @@
 
   android::binder::Status applyPayload(
       const android::String16& url,
-      const std::vector<android::String16>& header_kv_pairs,
-      const android::sp<android::os::IUpdateEnginePayloadApplicationCallback>&
-          callback,
-      int32_t* return_value) override;
+      const std::vector<android::String16>& header_kv_pairs) override;
+
+  android::binder::Status bind(
+      const android::sp<android::os::IUpdateEngineCallback>& callback,
+      bool* return_value) override;
 
   android::binder::Status suspend() override;